The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingEcm power source circuit
Description
When the ignition switch is turned on, the battery voltage is applied to the
igsw of the ecm. The output
signal from the mrel terminal of the ecm causes a current to flow to the coil,
closing the contacts of the
integration relay (efi main relay) and supplying power to either term ...
Using a bluetooth®
phone
The hands-free system is a function that allows you to use your
cellular phone without touching it.
This system supports bluetooth®. Bluetooth® is a wireless data
system that allows the cellular phone to wirelessly connect to
the hands-free system and make/receive calls.
Before making a pho ...
Ignition key cylinder light
Components
Removal
Disconnect cable from negative battery
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Place front wheels facing straight ahead
Remove steering pad ...